The present invention relates to folding chairs of the type comprising:
a first structure defining the front legs of the chair, PA1 a second structure defining the rear legs of the chair, PA1 a third structure defining the seat of the chair, and PA1 a backrest, PA1 wherein: PA1 a first structure defining the front legs of the chair, PA1 a second structure defining the rear legs of the chair, PA1 a third structure defining the seat, and PA1 a backrest, PA1 in which: PA1 characterised in that:
a) said three structures are provided with means for reciprocal articulation around a common axis, PA2 b) said means for reciprocal articulation includes stop means which limit the angular movement of each of said structure with respect to another one of said structure, so that the chair is able to assume a flattened folded condition and an unfolded condition of use. PA2 a) said three structures are provided with means for reciprocal articulation around a common axis, PA2 b) said means for reciprocal articulation includes stop means which limit the angular movement of each of said structures with respect to another one of said structures, so that the chair is able to assume a flattened folded condition and an unfolded condition for use, PA2 c) said backrest is defined by a fourth structure separate from said three structures and pivotally mounted on one of these three structures around said common axis, PA2 d) there are provided spring means to oppose a rotation of said fourth structure causing a backward tilting movement of the backrest, and PA2 e) there are provided auxiliary stop means which limit the backward tilting movement of said backrest.
A chair of the above indicated type is described and illustrated in U.S. Pat. No. 3,705,744 of the same inventor. In the known chair illustrated in this document, the backrest is rigidly connected to the front legs and therefore it forms an integral part of said first structure defining the front legs. More specifically, in the known solution, the backrest and the front legs of the chair are defined by a single rectangular frame, whereas the rear legs are defined by a U-shaped frame arranged inside the rectangular frame. Finally, the seat is defined by a further structure arranged inside the U-shaped frame, the above mentioned three structures being articulated to each other around said common axis by means of two side hinges. Each of said hinges is provided with stop means. Such stop means allow the seat to rotate with respect to the U-shaped frame from a position coplanar therewith to a position defining an angle with respect to the U-shaped frame. The U-shaped frame on its turn can rotate with respect to the rectangular outer frame from a position coplanar therewith to a position defining an angle therewith. In this manner, the above mentioned known chair can assume a fully folded flattened position as well as an unfolded position for use. At the same time, when the rectangular frame and the U-shaped frame are in their opened position, corresponding to the condition in which the chair is able to stand stably on the floor, the seat may be rotated from a condition for use to a raised condition, to make the passage easier for people walking between two subsequent rows of chairs.
The above mentioned known chair is therefore of convenient and effective use while at the same time having an extremely simple and reliable structure which is also aesthetically appealing.